Honestly, the one thing I've found is that outside factors never effect how my juice tastes. I'll be smoking a cigarette and drinking coffee outside the vape shop, then go in and sample all of their juices which they have in somehow indestructable CE4's, and the juice will taste great as ever. For me, it's more that with my devices at home, they just act bipolar as all get out, the device doing it. It happens wether I drink or smoke anything or not. I'm doing alcohol rinses from now on because my big thing is I think it's just factory residue getting swished and swashed around once the juice is filled up.